St. Augustine grass, or as it is known in South Carolina, Charleston grass, is arguably the most popular choice for lawns throughout the southern United States, and displays a high shade tolerance when compared to most other varieties of grass. Of the eleven cultivars—cultivated varieties—of St. Augustine, the most shade tolerant are Seville, Sapphire, Palmetto, and Bitter Blue.
These shade-tolerant cultivars also do well in direct sunlight, flourishing in only five to six hours of sunlight. The most popular cultivar of St. Augustine, Floratam, needs at least six to eight hours of sunlight a day.
Remember that lawn turf with a relatively high shade tolerance requires diligence. An obvious example is areas of grass that grow under trees. These areas must compete with tree roots for space, soil, water, oxygen, and nutrients. Tree roots can reach further than you’d expect, and sometimes the price of a healthy lawn is trimming the lower branches, or even complete removal of the offending tree.
Avoid high foot traffic in areas where you have planted a shade tolerant cultivar. You should also increase the mowing height to the highest recommended for the particular cultivar you have chosen. This method leaves more area on the grass blades to absorb sun.
Too much shade can make grass thin. One easy solution is to mulch the area. You can plant a groundcover, but that’s more difficult. Whatever the case, there’s generally no reason to use a shade-tolerant variety of grass in one section, and a less shade-tolerant variety in another section, of your lawn.
While St. Augustine is a reasonably shade-tolerant species, its varieties can be ideal for certain landscapes. When you understand the options available to you, as well as the needs and demands of shade-tolerant grass, you will cultivate an attractive and healthy lawn.